AVFoundation camera zoom

Question

I use AVFoundation framework to display video from camera.

The code how i use it is usual:

session = [[AVCaptureSession alloc] init] ;
...   
captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
...
[cameraView.layer addSublayer:captureVideoPreviewLayer];
...

So i want to add zoom function to camera.

I have found 2 solutions how to implement zoom.

First : is to use CGAffineTransform:

cameraView.transform = CGAffineTransformMakeScale(x,y);

Second : is to put cameraView in the scroll view ,set up max and min scrolling and set this view as zooming view.

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return cameraView;
}

What is the best way to make zooming better performance and quality? Are there any else solutions to make zoom? Maybe i missed some AVFoundation methods for zooming.

Thank you.

Answer 1

Well there is actually a GCFloat called setVideoScaleandCropFactor.

You can find the documentation here.

I'm not sure if this is just for still image output but I've been working on it and it does well if you set it to a gesture or a slider and let that control the float.

You can find a demo of it here.

Good stuff. Im trying to loop it so I can create a barcode scanner with a zoom. What im doing is rough though haha.